Control apparatus



March 2, 1965 ALLlsON 3,171,180

CONTROL APPARATUS Filed Sept. 23, 1963 FIG. I

llllllllll II INVENTOR. OBERT L. ALLISON ATTORNEY United States Patent 3,171,180 CONTROL APPARATUS Robert L. Allison, Seattle, Wash, assignor to Honeywell Inc., a corporation of Delaware Filed Sept. 23, 1963, Ser. No. 310,795 3 Claims. (Cl. 24-123) This invention relates to a disengageable release mechanism for use with a cable supporting a load which upon command will disengage to separate the cable and release the load. The invention may be used for example in underwater investigations where rather heavy scientific apparatus is lowered by a cable to a predetermined position under the water and anchored there for the duration of the investigation. After terminating the investigation rather than hoist the entire anchor cable back to the ship, it has been found desirable to cause the cable to part below the scientific apparatus thereby abandoning the anchor and causing the apparatus to either float to the surface or to be hauled to the surface by means of a cable.

In the past the cable below the apparatus has been severed by means of an explosive bolt arrangement having electrical connections from the bolt up to the surface. The apparatus usually comprises two members each of which has a connection to one part of the cable below the apparatus which members are joined together by an explosive bolt. Upon energizing the bolt from the surface the bolt is caused to explode and rupture thereby separating the two members thus parting the cable.

It has been found however that in the prior art apparatus the two members are joined by the bolt in such a manner that the bolt is under considerable tension. Since the standard explosive bolt has been hollowed out so as to accommodate the explosive charge its tensile strength has been considerably diminished. Thus a severe limitation on the weight of the load is experienced due to the tensile strength limitation of the explosive bolt.

The present invention overcomes this shortcoming by providing an apparatus incorporating an explosive bolt and wherein the forces along the cable act upon the apparatus with a shear force rather than a tensile force. These shear forces can be transferred to a special shear loading pin so as to substantially remove all shear forces from the bolt itself. By use of the invention the tensile force on the bolt itself is reduced to a minimum and the shear force is taken almost entirely by the shear loading member and yet the apparatus is operable to reliably and quickly sever the cable upon exploding the bolt.

Briefly the invention comprises two members joined together by an explosive bolt. Each of the members has a ring for attachment to the cable to be separated and one of the members has a shear loading pin which normally fits in a shear bearing hole in the other member. The load is applied to the rings in a direction which is not parallel to the axis of the bolt or with the direction of separation of the two members but is rather more nearly perpendicular to this direction. In other words the greatest component of the force applied by the load to the release mechanism acts in a direction perpendicular to the axis of the explosive bolt and to the direction of separation of the two members when the bolt explodes. Thus the forces acting on the mechanism do not cause a great tension force in the bolt but rather a shear force is exerted. A shear loading member extending from one of the members and abutting a shear loading surface on the other member absorbs most of this shear force so that in effect there is very little force from the load actually exerted on the weakened explosive bolt. A more complete understanding of the invention will be obtained upon an examination of the following specifications, claims and drawings in which:

FIGURE 1 is an exploded view of one embodiment of the present invention; and

FIGURE 2 is a cross-sectional view of the present invention in its assembled position.

In the drawing a generally cylindrically-shaped end link It) is shown having a back face 11 and a front face 12. The back face or surface 11 is beveled to form a surface 13 so as to permit the use of the unit over sheaves. The end link 18 has a pair of apertures 14 and 15 which accommodate bolts such as 16 shown in FIGURE 2 for the purpose of holding the apparatus together for storage to prevent accidental separation of the units. On the front face 12 of end link 18 is a generally cylindrical protrusion or shear bearing pin 17. End link 10 also has a ring-shaped cable attachment member 20 attached to the lower portion thereof by any suitable means such as welding.

Also shown in the figures is a body member 25 having a generally cylindrical shape and a front surface 27 and back surface 28. Front surface 27 has a generally circular inset portion 30 which is slightly off the center line of the member 25.

Through the front surface 27 and the indented surface 38 are a plurality of holes 33, 34, 36 and 38. Holes 33 and 34 are threaded so as to receive the bolts which pass through apertures 14 and 15 in member 10 and to thus hold the two elements together for storage. Hole 36 is located substantially centrally of the indented circular portion 30 and accommodates the explosive bolt shown in FIGURE 2 which extends from aperture 36 towards member 19 through a sealing ring 40. This explosive bolt engages with a threaded aperture 44 in member 10 which can be seen with reference to FIGURE 2.

Aperture 38 in member 25 is so positioned as to cooperate with the shear loading pin 17 when the members 10 and 25 are assembled together.

Member 25 also has a ring-shaped cable attachment member 48 connected thereto by suitable means such as welding. A watertight electrical connection 50 is shown having electrical terminals 52 and 53 mounted in member 25 through an aperture 55 in the side thereof. Terminals 52 and 53 are the electrical connections used to ignite the explosive bolt and suitable connection to these terminals is made by apparatus not shown from the surface vessel. A ring-shaped sealing member 60 is shown in the figures having a rubber sealing insert 63 therein and a plurality of apertures 65 therethrough. An end cover 67 having a like plurality of apertures 68engages the sealing ring 60 and the back surface 28 of member 25 to provide a watertight end cover. Suitable bolts 69 shown in FIGURE 2 pass through apertures 68 and 65 into threaded apertures in the back surface 28 of body member 25 to secure the cover in its normal position.

In assembling the apparatus of FIGURE 1 the explosive bolt 75 is placed through an indented cavity 70 in the body element 25 and through an aperture 77, aperture 36, sealing member 48 into threaded aperture 44 in end link 10. The bolt 75 is then tightened into the threaded aperture 44 of end link 10 drawing the end link 10 and the body member 25 together. The shear loading pin 17 of end link 10 is guided into the aperture 38 of body member 25. Bolt 75 is tightened until the washer 48 provides a watertight seal around the bolt. The washer 40 has a smaller circumference than the indented surface 30 and as can be seen water is allowed to flow into the cavity formed by surface 30 of body member 25 and surface 12 of end link 10 but is blocked from the explosive bolt by the sealing ring 48. By allowing the water to flow into this area the hydrostatic force tending to hold U body member 25 and end link it together when the ap paratus is submerged in the water is minimized.

After end link is tightened securely against the body member 25, the bolts 69 are passed through apertures 68 and 65 of end covers 67 and sealing ring 56 respectively, and are tightened on to the back surface 28 of body member 25 to thus provide a watertight seal to the interior electrical connections of the explosive bolt. Bolts such as 16 may be passed through apertures 14 and of end link It) and tightened into threaded apertures 33 and 34 of body element while the apparatus is being stored. Prior to usage, however, the bolts pass ing through apertures 14 and 15 are removed. Cables 79 and 80 shown in FIGURE 2 may then be attached to ring-shaped members 25 and 48 respectively at the point where it is desired to separate the cable.

Referring now to FlGURE 2 which shows the members in their assembled condition the explosive bolt 75 is seen passing through an indented cavity formed by aperture 75 in the back surface of body member 25 and through aperture 77, aperture through the sealing member and into the threaded aperture 44 of end link 10. It is noticed that aperture 36 has a slightly larger circumference than aperture 77 through the body member 25. This enlarged circumference permits the expansion of gases upon rupturing of the explosive bolt 75 to tend to force end link llti away from body member 25. This enlarged area also permits bolt 75 to flare out upon rupture and prevent the bolt head from being thrust to the left since the flared out portion will bind in the smaller diameter aperture 77. This prevents damage to the end covers and electrical connections associated with body member 25 so that they may be reused after recovering the cable.

It is also seen that cables 7? and 89 when attached to the ring members 2%) and i3 apply forces at a slight angle to a line perpendicular to the axis of explosive bolt 75. By this arrangement the greater component of forces exerted on the release mechanism is in a direction perpendicular to the axis of bolt 75 which is a shear force and that only a small component of this force acts on bolt 75 in tension. The shear bearing pin 17 cooperates with the aperture surface 38 in such a manner that the component of forces exerted upon the cables 79 and 80 is exerted against the shear bearing pin 17 which can be made strong enough to support great shear forces. It is also seen that the electrical connections are not exposed to the water by virtue of the sealing action of sealing members 60, 4-6 and the watertight electrical connection Stl although water is allowed to the space between the end link 10 and body member 25.

When it is desired to part the cable an electrical signal is sent from the surface vessel to the electrodes 52 and 53 to cause ignition of the explosive mixture in bolt 75. The bolt 75 ruptures in the enlarged aperture 36 to cause a fracture of the bolt near the surface 30 of the body member 25. The gases released by this explosive rupturing of bolt 75 tend to push end link 16 away from body member 25 against the hydrostatic force on the outside of these members. The shear loading pin 17 is made short enough that upon rupture of bolt 75 the end link 10 may rotate and pin 17 escape from aperture 38 without binding.

It is seen that with the apparatus of FIGURES l and 2 a greater load may be placed on the release mechanism than heretofore possible since the force exerted on the release mechanism is not in tension but is rather in shear and this shear force is substantially entirely taken up by the strong shear pin associated with end link 10. It is also seen that the force resulting from the load on cables 79 and 80 aids in the separating of the two elements 10 and 25. Thus when bolt 75 fractures, the load exerted by cables 79 and 80 will cause member 10 to rotate about its lower portion against body member 25 and shear bearing pin 17 will escape aperture 38 so that the two portions of the release mechanism will separate.

Many modifications will occur to those skilled in the art, for example, if desired, the sealing member 40 may be removed from its location in FEGURE 2 and placed between the head of the bolt 75 and the body member 25. By this expedient all of the hydrostatic force exerted between end link 10 and body member 25 would be eliminated since Water would be allowed to entirely fill the cavity between surface 35 of body member 25 and surface 12 of end link 10. Also it is clear that the electrical connection 55 could be placed easily in the end cover 68 as an integral part thereof in which case only two sealing rings such as 4%) and 55 would be necessary. Likewise while I have shown a shear bearing pin 17 cooperated with a bearing aperture 38 to absorb the shear stress caused by cables 79 and be acting on the release mechanism, any other suitable configuration of shear bearing surfaces could be employed. For example, release link ltl could have a portion thereof extending to the left to form a shear bearing surface and body member 25 having an indentation thereon to receive the shear bearing portion and cooperates therewith. In other words the configuration shown for the shear bearing pin 17 of FIGURE 2 should not be considered a limiting factor since other shear bearing surfaces lying parallel to the axes of the explosive bolt 75 could also be employed so long as the two can readily absorb the shear stresses placed on the mechanism and can separate easily without binding. I therefore do not intend to be limited by the specific embodiment shown herein but intend rather to be limited by the following claims.

1. Releasable linking apparatus comprising, in combination:

a first member having an aperture therein, the aperture having an enlarged portion; a second member having an aperture therein, said first and second menbers normally joined together by an explosive bolt mounted in the apertures of said first and second members, the bolt exerting a force on said first and second members along a first axis with the enlarged portion of the aperture in said first member providing space for the bolt to fracture;

said first member having a shear bearing protrusion extending into a corresponding shear bearing cavity in said second member when said members are joined by the bolt, a surface of the protrusion abutting a surface of the cavity, the abutting surfaces extending in a direction substantially parallel with the first axis; and

means attached to said first member and said second member to exert forces thereon at an angle to the first axis so that a component of the forces tends to press the abutting surfaces together.

2. Releasable linking apparatus for use with a cable comprising, in combination:

a first member having a shear bearing protrusion and having an aperture therein, the aperture having an enlarged portion;

a second member having a shear bearing cavity and having an aperture therein;

an explosive bolt, said bolt being placed in the apertures of said first and second members and operable to join said first member to said second member so that the shear bearing protrusion of said first member extends into and abuts the shear bearing cavity of said second member in the direction of the axis;

cable attachment means connected to said first member and to said second member on substantially opposite sides thereof when said members are joined by said bolt, said cable attachment means normally exerting forces in opposite directions on said first member and said second member tending to cause face on substantially opposite sides thereof, said first member having an aperture extending therethrough from the first surface to the second surface, the aperture having a first cross-sectional area near the first surface and an enlarged cross-sectional area near the second surface, said first member also having a shear bearing surface extending generally parallel to but displaced by a first distance from the aperture;

an explosive bolt having a threaded shank of the first cross-sectional area;

a second member having a first surface and a threaded aperture extending thereinto through the first surface, said second member having a shear bearing surface extending generally parallel to but displaced by a distance substantially equal to the first distance from the aperture, said bolt extending from the first surface through the aperture of the first member and threaded into the aperture of the second member to join the first member to the second member With the shear bearing surface of said first member in substantial contact with the shear bearing surface of said second member;

cable attachment means connected to said first member and said second member on substantially opposite portions thereof When joined by said bolt, said cable attachment means being operable to exert forces on said first member and said second member tending to press the shear bearing surfaces together; and

means connected to said bolt to cause explosion thereof, the enlarged cross-sectional area of the aperture of said first member providing space for said bolt to fracture to thereby unjoin the first member and the second member.

References Cited by the Examiner UNITED STATES PATENTS 2,489,984 11/49 Shoemaker 29483.1 2,585,870 2/52 Spielman.

2,650,127 8/53 Carlson 294-831 2,715,872 8/55 Klas 29483.1

FOREIGN PATENTS 832,837 4/60 Great Britain.

DONLEY I. STOCKING, Primary Examiner. 

1. RELEASABLE LINKING APPARATUS COMPRISING, IN COMBINATION: A FIRST MEMBER HAVING AN APERTURE THEREIN, THE APERTURE HAVING AN ENLARGED PORTION; A SECOND MEMBER HAVING AN APERTURE THEREIN, SAID FIRST AND SECOND MEMBERS NORMALLY JOINED TOGETHER BY AN EXPLOSIVE BOLT MOUNTED IN THE APERTURES OF SAID FIRST AND SECOND MEMBERS, THE BOLT EXERTING A FORCE ON SAID FIRST AND SECOND MEMBERS ALONG A FIRST AXIS WITH THE ENLARGED PORTION OF THE APERTURE IN SAID FIRST MEMBER PROVIDING SPACE FOR THE BOLT TO FRACTURE; AND FIRST MEMBER HAVING A SHEAR BEARING PROTRUSION EXTENDING INTO A CORRESPONDING SHEAR BEARING CAVITY IN SAID SECOND MEMBER WHEN SAID MEMBERS ARE JOINED BY THE BOLT, A SURFACE OF THE PROTRUSION ABUTTING A SURFACE OF THE CAVITY, THE ABUTTING SURFACES EXTENDING IN A DIRECTION SUBSTANTIALLY PARALLEL WITH THE FIRST AXIS; AND MEANS ATTACHED TO SAID FIRST MEMBER AND SAID SECOND MEMBER TO EXERT FORCES THEREON AT AN ANGLE TO THE FIRST AXIS SO THAT A COMPONENT OF THE FORCES TENDS TO PRESS THE ABUTTING SURFACES TOGETHER. 